Extraction of Reflectivity From Microwave BlackBody Target Using Free-Space Measuements

Published

July 24, 2011

Author(s)

Dazhen Gu, Derek A. Houtz, James P. Randa, Dave K. Walker

Abstract

We report on the characterization of blackbody target reflections as part of the recent progress on the development of brightness temperature standards for microwave remote sensing at the National Institute of Standards and Technology (NIST). The very low reflections from the blackbody targets used in airborne or satellite remote sensing systems present challenges to the extraction of reflection coefficients from the measurements. A full calibration technique is developed for this study by use of a flat aluminum plate made as a known standard in combination with measurements of the empty anechoic chamber. The theoretical basis and measurement procedures, along with uncertainty analysis, are presented. Calibration results validate the method by showing its independence from measurement hardware and conditions. A comparison between the theoretical prediction of reflection coefficients of a free-standing dielectric slab with traceable physical parameters and the de-embedded reflection coefficients from experiments confirms good calibration accuracy. The specific blackbody target used in this study shows well matched properties with a power reflectivity below -40 dB over the entire measurement band (18 GHz to 26 GHz). We report on the characterization of blackbody target reflections as part of the recent progress on the development of brightness temperature standards for microwave remote sensing at the National Institute of Standards and Technology (NIST). The very low reflections from the blackbody targets used in airborne or satellite remote sensing systems present challenges to the extraction of reflection coefficients from the measurements. A full calibration technique is developed for this study by use of a flat aluminum plate made as a

Conference Dates

August 1-5, 2011

Conference Location

Sendai

Conference Title

International Geoscience & Remote Sensing Symposium

Pub Type

Conferences

Download Paper

https://doi.org/10.1109/IGARSS.2011.6050070

Keywords

Anechoic chamber, blackbody target, free-space calibration, reflection measurement, uncertainty analysis

Citation

Gu, D. , Houtz, D. , Randa, J. and Walker, D. (2011), Extraction of Reflectivity From Microwave BlackBody Target Using Free-Space Measuements, International Geoscience & Remote Sensing Symposium , Sendai, -1, [online], https://doi.org/10.1109/IGARSS.2011.6050070 (Accessed October 14, 2024)